okay this is a little long but here goes, i changed the spark plugs out last week and the #2 cylinder was stripped in the head but i still got the plug in with about 2 or 3 threads sticking out. it still runs fine. now last monday i goto work and i'm on the interstate doin about 70 when my car starts runnin like shit and it sounds like it's blowing something out underneath the car. i get off of work tuesday morning and it does the same thing till i get to the gas station and look at it, then when i start it back and drive it still hesitates but dont make the loud blowing sound anymore and hasnt done it since. now everyday since then when it warms up it starts hesitating when i'm cruising along or sitting at a stoplight light. most of the time when give 1/2 throttle or more it will run fine but still feels a little sluggish. it's only hesitated bad on acceleration once or twice. now, any suggestions?